化学机械抛光参数对声发射特征的影响

摘要

Chemical mechanical polishing (CMP)is a dominating way to realize global planarization of wafers, and acoustic emission is very sensitive to material damage.So it is of great significance to investigate acoustic emission characteristics during CMP for CMP mechanism research and process monitoring.Here acoustic emission characteristics and signal generating mechanism during CMP were studied using copper,a kind of interconnection material of semiconductors.The results demonstrate that the intensity of acoustic emission signal increases with the increase of polishing pressure and pad rotational speed.The signal is obviously influenced by the ingredient of liquid pumped in as well.Besides,signal energy distributes mainly within two frequency bands,and the higher frequency component is able to characterize scratches during CMP.%化学机械抛光(CMP)是实现晶圆全局平坦化的主要手段,分析CMP过程的声发射特征对探究CMP机理、监测CMP过程具有重大意义.以半导体互连材料铜为对象,分析铜CMP过程的声发射特征,探索CMP过程产生声发射(AE)信号的机制.研究发现:随着抛光压力和抛光垫转速的增加,AE信号强度增大;CMP过程通入的液体成分对AE信号有较明显的影响;AE信号的能量主要分布在两个频段,其中高频成分能够表征CMP过程的划痕.